South America, alongside Europe and Pacific islands and China, has been well-Known battlefield of WW2. So here is a challenge: With PoD of 1933, prevent South American theater from opening in WW2.
Maybe if the Graff Spee doesn't sail to the Falklands during its South Atlantic raid and ends limping towards Stanley you can still keep Argentina from sending its fleet to invade the place to, ehem, "get the Germans away from the Americas", which in turn snowballed in South American crisis of January 1940, when Argentina entered the war on the Allied side even though the Allies didn't want her in at that time, and regional rivalries because of the dreadnought race lead to Chile and Brazil giving basing rights to the German submarines and naval patrol aircraft hoping they'll attack the (by then powerful but outdated) Argentine Navy.I don't think you can keep Argentina out of it. They were going to make a bid for the Falklands.
The hilarious part was the Bolivian forces trying to invade Mato Grosso, they ended recalling the invasion before the brazilian troops arrived to face them due the massive attritionNot to mention avoiding revanchism in Bolivia over losing Chaco war, which led them to join the axis and invade Paraguay and Brazil.
Which proved to be a mistake when Bolivia invaded Brazil. It was an equivalent of Operation Barbarossa for Brazil. As that docking rights pact was equivalent to Molotov-Ribbentrop pact for Brazil.Brazil giving basing rights to the German submarines and naval patrol aircraft hoping they'll attack the (by then powerful but outdated) Argentine Navy.